Fix CSR test to run on 1.19+ (#34496)
Fix CSR test to run on 1.19+ (#34496)

https://kubernetes.io/docs/reference/access-authn-authz/certificate-signing-requests/

Introduced in 1.19, not 1.18
istio/istio,istio/istio,istio/istio,istio/istio,istio/istio